The Node (from the Latin “nodus” which means “a knot”) is any computer that is connected to the network in the blockchain system. To maintain contact with each other and transmit data about blocks and completed transactions, nodes on the blockchain use the P2P (peer-to-peer) protocol. In a few words, a node is any computer connected to any cryptocurrency network and storing a part of the information from this network.
After loading all transactions, the blockchain node starts checking the received information.
The main tasks are:
- Detection of incorrect transactions;
- Protect peer-to-peer network integrity.
Blockchain nodes distributed around the world provide secure transactions. They are the main technology responsible for moving funds along the chain. So, if one blockchain node notices a violation of transaction rules within the system, then the operation is rejected, even if all the other nodes have confirmed its legitimacy.
This distribution structure of communication nodes with equal rights ensures the decentralization and security of cryptocurrencies. It is important that each node retains a copy of the blockchain since this defines the blockchain as both distributed and decentralized.
Nodes help ensure that the integrity of the information is not altered. If someone tried to tamper with the blockchain retroactively it would appear changed on that one node only. All the other remaining blockchain nodes would display the ‘true’ copy of the blockchain. This helps categorize the network as a decentralized one since no central authority can have full control over the information being stored on a blockchain.
The node types
The blockchain node stores a part of the data, or a complete chain of network blocks. It depends on the node type, which we list below.
There are several types of nodes:
- Full nodes are a group of nodes that are completely independent of each other and store all the data of the blockchain. The peculiarity of such blockchain nodes is that they work completely autonomously from each other and do not trust the solution of other nodes. They download and confirm new transaction blocks, applying the rules set by the consensus algorithm. If the established rules are violated in a particular translation or in the whole block, the full node rejects it and doesn’t add it to the general blockchain. One of the most important characteristics of full nodes is that they always control the execution of predefined algorithms. They can even temporarily “isolate” a source that tried to conduct an incorrect transaction. In a few words, such blockchain nodes guarantee the highest security of the system and transfers within it. To set up a full node, you need to install full-fledged crypto wallets on your PC. During their installation, a full blockchain is downloaded to the hard disk. All cryptocurrencies operating on the PoW (Proof-of-work) algorithm are supported by the operation of full nodes. Bitcoin node is a full node that stores all transaction information.
- Lightweight nodes are a group of blockchain nodes with less autonomy. They store only the headers of transaction blocks on the network and depend on full nodes. Lightweight nodes automatically accept the opinion of the biggest part of blockchain nodes. Many light wallets are multi-currency wallets, which allows you to store several digital assets on them at once. However, during transactions, users do not access their blockchain. They use third-party services, which reduces the level of anonymity. Lightweight nodes can confirm incorrect transactions. Of course, an error will be detected in the near future, since all translations are checked at full nodes. However, a defect may result in a financial loss. Among the wallets that allow you to become a lightweight node owner, you can distinguish Electrum, Jaxx wallet, Exodus.
- The Masternode is a specially adapted full node that acts as a trusted node. It’s a cryptocurrency wallet which is connected to the network with a placed deposit. That is, the owner of the masternode sets up full-fledged wallets, downloads the entire blockchain, and then fulfills additional conditions to establish a masternode. Mastrenodes store all transaction information on the network, while other nodes do not record transactions. Compared to full nodes, masternodes cannot add blocks to the blockchain. Their sole purpose is to keep track of transactions and verify them. However, an additional advantage is that by launching a masternode, you not only protect the network, but can also receive a share of the reward for your services. To establish a masternode, one needs to block a certain amount of funds as collateral. The masternode cryptocurrencies typically support or operate on the PoS (Proof-of-Stake) transaction confirmation algorithm. These include Dash, Harvest Masternode Coin, Numus (NMS), Solaris, Horizen, PIVX.
- The Supernode is a masternode that operates without a wallet and acts as the endpoint of the cryptocurrency API. The supernode is represented only in the NEM network. Accounts with 3,000,000 XEM or more can manage the supernode from a local computer or from a cloud server. Supernodes should work 24 hours a day, processing all transactions.The NEM network has two levels. The supernode level keeps the system powerful and fast, while ensuring efficiency and optimal performance. This multi-level design allows the second level of wallets and third-party applications to use the full network without downloading or processing the entire blockchain. For this work, supernode owners receive a daily XEM reward divided equally among all supernode owners.
Considering the question of what a blockchain node is, it is worth noting that it is the nodes that dictate the rules. Miners receive transactions confirmed by a blockchain node. By launching the node, the user is able to control his/her own funds, trusting only consensus algorithms. In addition, some people believe, that buying a promising digital currency that has recently entered the cryptocurrency market and launching a masternode for it, they can get passive income.